implemented JPX images.

Legacy/Saiki/ImageJPX.cs

@@ -0,0 +1,126 @@
+//! \file       ImageJPX.cs
+//! \date       2017 Dec 06
+//! \brief      Obfuscated images.
+//
+// Copyright (C) 2017 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System.ComponentModel.Composition;
+using System.IO;
+using GameRes.Utility;
+
+namespace GameRes.Formats.Saiki
+{
+    public abstract class ObfuscatedImageFormat : ImageFormat
+    {
+        const int DefaultEncryptedLength = 200;
+
+        internal static IBinaryStream OpenEncrypted (IBinaryStream input, int encrypted_length = DefaultEncryptedLength)
+        {
+            input.Position = 0;
+            var header = input.ReadBytes (encrypted_length+2);
+            header[0] ^= 0xFF;
+            header[1] = Binary.RotByteL ((byte)~header[1] , 1);
+            int shift = 1;
+            byte count = header[0];
+            for (int i = 2; i < header.Length; ++i)
+            {
+                header[i] = Binary.RotByteL (header[i], shift);
+                if (++shift >= 7)
+                    shift = 1;
+                if (--count == 0)
+                {
+                    if (shift <= 4)
+                        count = header[1];
+                    else
+                        count = header[0];
+                    shift = 1;
+                }
+            }
+            Stream stream = new StreamRegion (input.AsStream, header.Length, true);
+            stream = new PrefixStream (header, stream);
+            return new BinaryStream (stream, input.Name);
+        }
+    }
+
+    [Export(typeof(ImageFormat))]
+    public class JpxFormat : ObfuscatedImageFormat
+    {
+        public override string         Tag { get { return "JPX"; } }
+        public override string Description { get { return "Obfuscated JPEG image"; } }
+        public override uint     Signature { get { return 0; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public JpxFormat ()
+        {
+            Signatures = new uint[] { 0x38FF9300, 0 };
+        }
+
+        public override ImageMetaData ReadMetaData (IBinaryStream stream)
+        {
+            var header = stream.ReadHeader (2);
+            if (header[0] != 0 || header[1] != 0x93)
+                return null;
+            using (var jpg = OpenEncrypted (stream))
+                return Jpeg.ReadMetaData (jpg);
+        }
+
+        public override ImageData Read (IBinaryStream stream, ImageMetaData info)
+        {
+            using (var jpg = OpenEncrypted (stream))
+                return Jpeg.Read (jpg, info);
+        }
+
+        public override void Write (Stream file, ImageData image)
+        {
+            throw new System.NotImplementedException ("JpxFormat.Write not implemented");
+        }
+    }
+
+    [Export(typeof(ImageFormat))]
+    public class BmxFormat : ObfuscatedImageFormat
+    {
+        public override string         Tag { get { return "BMX"; } }
+        public override string Description { get { return "Obfuscated BMP image"; } }
+        public override uint     Signature { get { return 0; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ImageMetaData ReadMetaData (IBinaryStream stream)
+        {
+            var header = stream.ReadHeader (2);
+            if (header[0] != 0xBD || header[1] != 0x59)
+                return null;
+            using (var bmp = OpenEncrypted (stream))
+                return Bmp.ReadMetaData (bmp);
+        }
+
+        public override ImageData Read (IBinaryStream stream, ImageMetaData info)
+        {
+            using (var bmp = OpenEncrypted (stream))
+                return Bmp.Read (bmp, info);
+        }
+
+        public override void Write (Stream file, ImageData image)
+        {
+            throw new System.NotImplementedException ("BmxFormat.Write not implemented");
+        }
+    }
+}